import { ContextManager, Observable } from '@zcomponent/core';
import * as THREE from 'three';
import { Light, LightConstructorProps } from './Light';
export type SpotLightConstructorProps = LightConstructorProps;
/**
 * A light that's emitted from a point in space, along a cone of increasing radius.
 *
 * Root element: [THREE.SpotLight](https://threejs.org/docs/index.html?q=SpotLig#api/en/lights/SpotLight)
 *
 * @zcomponent
 * @zgroup Lights
 * @zicon light
 * @ztag three/Object3D/Light/SpotLight
 * @zparents three/Object3D/Group/**
 */
export declare class SpotLight extends Light<THREE.SpotLight> {
    constructor(contextManager: ContextManager, props: SpotLightConstructorProps);
    /**
     * Maximum angle of light dispersion from its direction whose upper bound is Math.PI/2.
     * @zprop
     * @zgroup Light
     * @zgrouppriority 5
     * @zdefault 1.0471975511965976
     */
    angle: Observable<number, never>;
    /**
     * If set to true light will cast dynamic shadows.
     *
     * @Warning: This is expensive and requires tweaking to get shadows looking right.
     *
     * @zprop
     * @zgroup Light
     * @zgrouppriority 5
     * @zdefault false
     */
    castShadow: Observable<boolean, never>;
    /**
     * The amount the light dims along the distance of the light.
     * @zprop
     * @zgroup Light
     * @zgrouppriority 5
     * @zdefault 1
     */
    decay: Observable<number, never>;
    /**
     *
     * Percent of the spotlight cone that is attenuated due to penumbra.
     * Takes values between zero and 1. The default is 0.0.
     * @zprop
     * @zgroup Lights
     * @zgrouppriority 5
     * @zdefault 0
     */
    penumbra: Observable<number, never>;
}